Steel-heating furnace.



W. R. BENNETT.

STEEL HEATING FURNACE,

APPLlcAloN min Aue.1s.1911.

Patented Oct. 30, 1917.

2 SHEETS-SHEET l.

`9 Inv/@fnf W. R. BENNETT.

STEEL HEATING FURNACE,

APPLICATION FILED AUG. I6. 19H.

1,244,578. A Patented Oct. 0 917.

2 SHEETS-S 2.

wzuiLiL/iiuy E. BENNETT, or ELMwoon, CONNECTICUT.

-f STEEL-HEATING EUENACE.

\ f Specification of Letters Patent. Patented 001;, 30, 1917,

Application sieri August is, 1917. serial Np. 186,498.

'caZZ whom imag/'concern' e Be it known that IWILL1AM RL BENNETT, a citizen of the United States, residing'at Elmwood, in the county of Hartford and State of Connecticut, have yinvented certain new and useful Improvements 4in Steel- Heating Furnaces, of which the following is a specification. g

This invention `relates to a steel-heating furnace, being used for heating steel pieces of various kinds, in the hardening and tempering thereof. The furnace for illustration, is particularly .intended for the hardening or treatment of `highspeed or tungsten steel.- The primaryi motive I have in viewy isy the provision of an article of the character set forth byA which the preliminary or initial, secondary` orintermediate vand final or drawingheats'can be accomplished in a ready and 'quick manner. 4The @compartments which ,theseV operations consecutively occur are superimposed and, preferably are interiorly rcylindrical which is a desirable Astructure to insure the maximum effects in anyone given chamber. y,es a

- matterof factgI prefer `'that the ,furnaceV A beef cylindrical construction, although this.

may not always'be necessary.y Y e In the drawingsy accompanyingand form-i ingpart of the Apresent specificationy I have shown one of the severalL convenientforms ofembodimeni `0f the invention which I will set forth fully in thefollowing description. I amnot restricted to this showing, I may depart therefrom. in several respects within the scope of vhe invention, definedk byv the claims following said description.,V i

Referring to said drawings; Figure 1 is fa verticaly sectionalview of a furnace involving the invention. Figslg2 and ,f3 are horizontalfp, sections on the hnes2-f2 and 3-3 respectively of Fig.

1looking inthe direction: of the arrows.

y Jig, ,4f is. a detail ofthe upper portion of the furnace as seen from the front. Likecharactersrefer tolike .parts-throughke outthe several views. y c ,f I i The furnaceiis denoted `by Qand as shown itis fcylindrical, which as I have already noted isv the desirable but not essential con.- struction. Said furnace has three chambers or compartments asB, 4 andsy .which as shown are superposedandcoaxial.Y Said chambers or Compartments, 'f1 andv 5 are preferably cylindrical, .and I might. observe i` atthis point that it isr moredesirablethat the compartments be of this shape than the exterior of the furnace, although the latter has its advantages. r The furnace 2 as shown is mounted ony a suitable foundation or sup-v port as 6. Beneath the lowermost chamber 3 is disposed a heating chamber or combustion compartment as 7, the heat from which may be derived inrany convenient manner, preferably from a single or unitary heater as the oil burner 8 (or several of them if necessary), directed into the heating or fire chamberr 7 as will hereinafter more particularly appear.

Describing the furnace selected forV illustration more in detail, it comprises the base member 9 resting on the foundation or equivalent support 6 Aand which as shown .is of cylindrical ire-brick'or similar composition.

This cylindrical member or enlarged ,disky 9 sustains ther'circular brick 10 which kin turn supports the member a suitable floor for the'chamber 3V and also of re-brick, `the space between the two parts'9 and 11 and inclosedl by the ring orv band 10 presenting the fire or heating cham-` ber 7 to whichv I have already referred.

The lire-brick portion of the furnace which has thus far been partly described, is incased by a shell as 12preferably of metal and which consistsjusually of superimposed rings. Said shelll 4or housing 12 'extends from the support' 6 `to the top of the lfurnace. The ,lowermost band ofthe shell or housing 12 has a perforation 13 registering or coincidinguwith a perforation or opening inthe band or'ring 10, to receive the tip or nozzle portion of the burner 8. -In practice thisv burner will be provided with suitable regulating means ascommon. The diskr 11 isl surmounted by the band or ring 15, a`

or disk 11 constituting Y 11, 15and 16 presenting jointly the cham- Y ber 3 towhich I have already'alluded, and' all of themas will be understood being of. fire-brick or something of a similar nature.

Although I have described the parts l1 and 16 vasbeing of disk construction, I do.

not .necessarily mean to imply that they are circular. It V1s not imperative in fact that they becircular, although their main portions eachdenoted yby 17- are preferably so, as will lbe seenv bestI on inspectionof Fig.

' the heating or lire chamber 7 and the chamber 3 in turn is likewise inv communication with the chamber 4, so that the'he'at can rise to effect the proper action upon the con tents of the two chambers. T he tongue portions of theparts 11 and 1G, as will beenderstood, are flush with the outer surface of the body of the furnace.

The tongue portions 18 and 19 of the dividing piece 16 are surmounted by a ring or band'21, which is practically a-counter part of the band orring 15, although a trifle shallower.- yThisband 21 in turn is surmounted by the/circularelement or disk 22, the periphery of which is inthe plane 'of the outer surface ofthe fire-brick or analogous body of the furnace. This disk 22 constitutes the roofV ortop of the second or niiddlechamber 4. r1`he chambers 3 andv 4' have openings 23 and 24 respectively for the lintroduction of the necessary stock or articles-thereinto. 'Y 1 f' Alt iough these openings 23and 24 which as will loe-*understood correspond withvsimilar openings in theshell or jacket 12 may be covered in any desirable way, preferv to employ inconnection with each ofthem two doors denoted -respectively by 25 and 26, and 27 and 28., the doors 25 and226 coperatingV and aYV like statement apl'alying to the doors 27 Vand 2S. These doors are externally tapered, and they can be in each case sepa" rately or simultaneously opened, depending` upon the character of thestock tobe introduced into the compartments 3 and4'. 1f a smallpiece or pieces ofstock yare to be introduced into either or both of the coin-partments, the lower door can be opened, whereas iflarger pieces, both doors can be opened. The doors are preferably hinged as at 29 to l the metalshell 12, and their marginal portions when the doors are closed fit against the shell to lthoroughly shut the openings. rlhe bodies of the doors may be vof metal andv may ybe hinged as already described,

while the parts of the; doorswhich lit within the openings 23 yand-24 may be of fire-brick or equivalent substance To vfacilitate the draftin the initial or primary chamber 3 and the' consequent heating ofthe steel prior to `hardening and tempering, the said chamber may have extended therefrom near the upper side,l the .opening SOwhich draws the heat upward and thus accomplishes the desired object.v All of thechambers except as herein noted are imperforate and flueless, features of importance.

The arrows in Fig. 1 illustrate in part the path of the heat waves, the heat passing through the two lateral openings 2O from Vthe fire chamber 7 into the primarychamber 3 and from thence by way of similar openings 20 into the chamber 4`. Fitted closely within 'the upper portion 'of the shell r or jacket 12 and 'separated by a space as 31 from the disk 22 is the practically circular metal plate 32 which constitutesthebottoin of the upperV chamber 5,the wall of said n)e per chamber being thevr ring orband 38 of lire-brick or the like, which obviously is surL rounded by the metallic shell" 12, the upper edges of thev two lparts being' flush. This annular member orring 33 'and upper portion of the metal shell 12 are surmounted by the crown piece 34 which ymay be also of metal and whiclrlms a downt-urned --fiange 35 inclosing comparatively closely the top portion ,of 'the shell or ja-cket12- Said 'annue lar member or ring 3B'ha`s an'opening 36 whichV is a 'counterpart of 4the openings and 24 already described' andl :which is con-E trolledlby. doorsBT 1andBS, practically dupli# Cates of the doors already -set forth.

` The space 31 under the uppermosty cham-y ber has means such as the-openingsl or perforations 39, forthe admission of atmose plieric air,there being any desirable num= ber of at suitable intervals in the shell or jacket 12. They are controlled inthe present case by damper means as'the circular strip 40 whichy generally has'anupand down movement on the saidrshell 12 to cover more or less or en-v tirely theA series of openings 39 to kthereby regulate the temperaturein the topmost come` partment or vchambery 5. f

' This damper or circular stri-p 40 may beV operated Vin any desirable manner "preferably by a thermostat such as that denotedin these openings 39 which are formed general way by 41.V Said thermostat involves in its organization Y, a hollow body 42A surinounting the crown-or top, plate V34 prac# tically centrallyV thereof' and inclosingy the two thermostaticbars 43', duplicatesofeach other and secured atV their bases or lbutts to the outer or upper surface ofthe crown-plate 34. The two therniostatioelements43 practically cross andA to vtheir free endsare connected bands 44 and 45 which traverse ,gz'uide rollers each denotedby 46,'mounted1upon the crown plate 34. The bandf44- as shown isconnected tothe rear-endof the damper 40, while the band 45 is connected to thecross piece or bar 47 which in'fturn Vhas bands 48 connected toand depending therefromand united to the damper 40 near thel front end thereof as shown bestA in Fig. 4. In

connection withft'he upper chamber 5 isa-lsov a thermometer 49, the elongated base portion 50 of which extends through the roof or crown plate 34.

The compartment or chamber 4 rst receives the steel pieces to be hardened and tempered, and there is developed therein a suitable temperature which ordinarily does not exceed 1600 degrees Fahrenheit. After the steel kpieces have been in this chamber or compartment the requisite length of time, they are taken from thence and introduced into compartment 8 where they are subjected to a temperature in the neighborhood or 2250 degrees F. They are left in this intermediate chamber the desired length of time and are taken from thence, quenched and afterward yput into the topmost compartment 5 in which the temper is drawn.

What I claim is:

l. A. furnace for treating steel pieces, comprising three superposed heating chambers, a combustion compartment positioned immediately below the lowest chamber, passages disposed uniformly in or near the periphery of the floors of the two lowest chambers, to provide communication for the products of combustion through the two lowest l chamber below.

2.. A furnace for treating steel pieces, comprising' three superposed heating chambers, a combustion compartment positioned immediately below the lowest chamber, passages disposed uniformly in or near the periphery of the floors of the lowermost chambers, to provide Comunication for the products of combustion through the two lowest chambers, said uppermost chamber being out of communication with the products of combustion being heated by the heat of the chamber below, the furnace having an air space below the floor ot' the uppermost chamber and said chamber having means for the admission of air at given intervals to reduce or hold at a given degree the temperature of the uppermost chamber.

In testimony whereof I aiiix my signature in the presence of two witnesses.

WILLIAM It. BENNETT. Witnesses:

WALLACE B. GOODWIN, HEATH SUTHERLAND.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

